Ancestral Species:Mute Swan Modern-Day Species:Black Swan Latin Name:Cygnus sal-flumen Kingdom: Animalia Phylum: Chordata Class: Aves Order: Anseriformes Family: Anatidae Genus: Cygnus Species: C. sal flumen
HABITAT
The River Swan is found in the east and western parts of Australia. In the west, they are more common in the coastal areas and in the east, they are generally found more inland. They are increasingly populating areas in New Zealand as there are many rivers to settle on. The River Swan have also steadily declined in population in New Guinea as the area features mainly freshwater rivers. They have also been known to have become extinct in the European areas as they were unable to naturally sustain their own population there.
The River Swan were at first introduced into Eastern parts of Europe, as well as Southern parts of China, but failed to populate. As a result, the River Swan have only been known to occupy Australian, New Zeland, New Guinean areas. Though they were originally introduced as ornamental birds into China and Eastern Europe, they were highly valuable as decorations in European homes. They were also hunted until extinct in China due to their rarity and were sold at high prices as food. No introduction was necessary for New Zealand parts as the ancestors of the River Swan, the Australian Black Swan, also occupied this area.
River Swans are quite picky in their selections of settling points and are very nomadic, though they are known to not migrate passed the Australasian region. They have not been known to migrate in patterns, but some have been known to shift between Australia and New Zealand. The River Swans are known to habit mainly saltwater rivers as there are less underwater predators. Though they strictly inhabit saltwater areas, they have been seen in rare cases of temporary settlements in freshwater lakes. They choose their lakes where there is also easy access to vegetation on the riverbanks during breeding or shortage of underwater vegetation.
During times of heavy rainfall, River Swans usually do not move, and simply shelter themselves under rocks. While droughts occur, River Swans generally temporarily move to more humid areas. While breeding, River Swans move to rivers close to forests as they are unable to fly but can hide in vegetation or on the surface of the rivers accordingly.
ADAPTATIONS
Behavioral - Expression through posture By shifting their postures, River Swans may communicate with other Swans of their intentions. When they stretch their necks, they are warning other creatures to stay away. By flapping their wings, they indicate that they will take flight and that other swans should move out of its way. This adaptation arose due to increased intrusion and individual conflicts between swan as more and more small predators target young cygnets as food.
Behavioral - Increased vocal activity
River Swans have been known to have more vocal activity than any other species of swan. These sounds range from croaks, squawks and barking. By barking, they threaten foes and signal that they are not welcome to enter a River Swans territory. By squawking, River Swans keep their groups together while flying and in formation. This adaptation occurred due to stronger winds to fly in and colder climates that differentiates a River Swan's ability to fly compared to other River Swans, resulting in loss of group members and family.
Structural - Adjustable FeetRiver Swans have known to have feet that were webbed about halfway to allow easier maneuvering on land. They also can contract each toes when traveling on land to avoid tripping. This adaptation occurred to due to rising water levels, preventing access to much vegetation located underwater, therefore requiring more movement on land to access food.
Structural - Small teethThe River Swan has a small set of teeth to catch small fish that settle in the rivers. These teeth are able to the the fish and hold it long enough for the River Swan to take to land and eat. This adaptation arose to increased difficulty to access vegetation
underwater.
Physiological - Elongated Vocal Chords With elongated vocal chords, the River Swans are able to emit croaks of different frequencies for their young and mates to recognize. This physiological adaptation allows River Swans to find their families when separated for periods of time. This adaptation arose due to increased groups of River Swans and stealing of young ones which allowed stolen cygnets to return to their real parents.
River Swan
Ancestral Species: Mute Swan
Modern-Day Species: Black Swan
Latin Name: Cygnus sal-flumen
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Anseriformes
Family: Anatidae
Genus: Cygnus
Species: C. sal flumen
HABITAT
The River Swan is found in the east and western parts of Australia. In the west, they are more common in the coastal areas and in the east, they are generally found more inland. They are increasingly populating areas in New Zealand as there are many rivers to settle on. The River Swan have also steadily declined in population in New Guinea as the area features mainly freshwater rivers. They have also been known to have become extinct in the European areas as they were unable to naturally sustain their own population there.
The River Swan were at first introduced into Eastern parts of Europe, as well as Southern parts of China, but failed to populate. As a result, the River Swan have only been known to occupy Australian, New Zeland, New Guinean areas. Though they were originally introduced as ornamental birds into China and Eastern Europe, they were highly valuable as decorations in European homes. They were also hunted until extinct in China due to their rarity and were sold at high prices as food. No introduction was necessary for New Zealand parts as the ancestors of the River Swan, the Australian Black Swan, also occupied this area.
River Swans are quite picky in their selections of settling points and are very nomadic, though they are known to not migrate passed the Australasian region. They have not been known to migrate in patterns, but some have been known to shift between Australia and New Zealand. The River Swans are known to habit mainly saltwater rivers as there are less underwater predators. Though they strictly inhabit saltwater areas, they have been seen in rare cases of temporary settlements in freshwater lakes. They choose their lakes where there is also easy access to vegetation on the riverbanks during breeding or shortage of underwater vegetation.
During times of heavy rainfall, River Swans usually do not move, and simply shelter themselves under rocks. While droughts occur, River Swans generally temporarily move to more humid areas. While breeding, River Swans move to rivers close to forests as they are unable to fly but can hide in vegetation or on the surface of the rivers accordingly.
ADAPTATIONS
Behavioral - Expression through posture By shifting their postures, River Swans may communicate with other Swans of their intentions. When they stretch their necks, they are warning other creatures to stay away. By flapping their wings, they indicate that they will take flight and that other swans should move out of its way. This adaptation arose due to increased intrusion and individual conflicts between swan as more and more small predators target young cygnets as food.
Behavioral - Increased vocal activity
River Swans have been known to have more vocal activity than any other species of swan. These sounds range from croaks, squawks and barking. By barking, they threaten foes and signal that they are not welcome to enter a River Swans territory. By squawking, River Swans keep their groups together while flying and in formation. This adaptation occurred due to stronger winds to fly in and colder climates that differentiates a River Swan's ability to fly compared to other River Swans, resulting in loss of group members and family.
Structural - Adjustable FeetRiver Swans have known to have feet that were webbed about halfway to allow easier maneuvering on land. They also can contract each toes when traveling on land to avoid tripping. This adaptation occurred to due to rising water levels, preventing access to much vegetation located underwater, therefore requiring more movement on land to access food.
Structural - Small teethThe River Swan has a small set of teeth to catch small fish that settle in the rivers. These teeth are able to the the fish and hold it long enough for the River Swan to take to land and eat. This adaptation arose to increased difficulty to access vegetation
underwater.
Physiological - Elongated Vocal Chords With elongated vocal chords, the River Swans are able to emit croaks of different frequencies for their young and mates to recognize. This physiological adaptation allows River Swans to find their families when separated for periods of time. This adaptation arose due to increased groups of River Swans and stealing of young ones which allowed stolen cygnets to return to their real parents.
Bibliography
Fern Bank (2003).The Shapes of Birds Feet.
Retrieved on Wednesday, July 28th, 2010 from http://fernbank.edu/Birding/bird_feet.htm